What do you think?

Among all the unexpected charges faced on holiday, from checking bags on the plane to extras in hotels, the most pervasive and hard to quantify – until the bill lands – can be those for data roaming.

For me, it has been the stuff of nightmares and the cause of many “doh!” moments. Why did I check Google Maps on my smartphone for directions to a restaurant, prompting a tumult of data downloading to update the map? And did I really need to watch a YouTube video or let my emails download themselves automatically?

Burnt by the subsequent phone bills, I decided to exploit every technological means at my disposal during this summer’s break to make sure my phone connection was on a data diet.

Things are supposed to have improved in Europe at least since July 1. An EU directive came into force that put a ceiling of €0.70 (£0.55) per megabyte on data when roaming – some operators had been charging more than 10 times that – and the limit will come down to €0.20/MB in 2014.

However, I was taking no chances and armed myself with a Tep Pocket WiFi for my trip over from the US. The Tep, which works in 36 countries, is a palm-sized cellular modem made by Huawei, containing a chip that also turns it into a WiFi hotspot.

I had it posted to me ahead of departure, but a pick-up can be arranged at major airports on arrival and it can be dropped off there on your way back, or returned in a prepaid envelope.

The great thing about the Tep is that you know exactly how much you are paying for data. A week’s unlimited data in the UK costs about £43. If you choose a limited data package, the display shows how much data are being used and it can be easily topped up.

I connected to the 3 network and enjoyed speedy connections over WiFi to my phones, an iPad and a laptop. I made Skype calls and watched online video in good quality.

There are other tricks to keep the profits of mobile carriers down. The safety catch to set on your smartphone to prevent data being fired off is to go to its network settings and turn off cellular data. This still allows you to receive and make normal calls.

If you are worried about the cost of voice calls, a prepaid local Sim card is a good option. These are available from dispensing machines in airports or you can buy them in advance online.

OneSimCard has a good reputation and I also had good results with a Sim purchased from CellularAbroad.com, which also offers data Sim deals. Truphone’s Tru Sim can carry multiple numbers, such as a US and UK number, on the same card. The Tru app, meanwhile, lets you call over WiFi.

To make calls over WiFi only, I choose “airplane” mode on my smartphone, which shuts everything down, then I turn WiFi back on to make use of apps such as Skype.

Skype is useful in paying for WiFi access. Skype Credit can be used at more than 1m hotspots to pay for access by the minute, saving you having to register for another service and keeping costs down if you only need to check email and the web for a few minutes.

When outside the range of WiFi hotspots, using a data-frugal browser can keep roaming charges down. The Opera Mini mobile browser strips web pages to their essentials, reducing data downloaded by up to 90 per cent. It also has a data counter to monitor usage.

Maps are incredibly useful but can be incredibly expensive when travelling – they are very data-rich and constantly update themselves as you move around.

One option is to download maps ahead of the trip to view offline.

Stay.com provides guides and maps for 116 cities that can be stored on your device and therefore do not incur data charges when accessed. They can also interact with a GPS chip to give accurate positioning.

Google Maps also offers offline access. Just zoom into the map area you will be exploring and a menu option will make it available offline. The map section is then downloaded to your device and a much wider area can be viewed than on a simple city map.

Another Google offline feature, available in Gmail, lets you catch up with emails. I had installed the new Gmail Offline app in the Google Chrome browser, which stored several weeks of emails on the local drive of my laptop. I worked through these on a flight back to Los Angeles and then connected the laptop to the WiFi hotspot on my smartphone after we had landed and I was roaming free again.

All email replies were immediately sent as it synchronised with regular Gmail and there was the gratifying sight of my inbox emptying as the delete-email instructions were passed on.

This matched my satisfaction at my next phone bill – like the holiday’s fading memories, it was like I’d never been away.

Data to go: apps to track your travel adventures

FlightTrack Free (iOS, Android)

FlightTrack users have been prepared to pay £2.99 for this excellent app and £6.99 for the Pro option, but a free version finally appeared in August. Its limitations are that you can only follow one flight at a time, but there is a new interface that overlays information about departure, arrival and gate number on a satellite map with the plane’s current location. The Google maps are zoomable and more than 16,000 airports and 1,400 airlines are covered. The Pro version adds features such as seating information and weather forecasts.

HipGeo (iOS, Android, free)

Social travel is in vogue with apps such as HipGeo, Trippy and Stay.com, Trippy allows you to collect and share travel ideas and collaborate on plans. HipGeo is a mini-blogging app that makes it easy to tell the story of your holiday and share it with friends. It can use an iPhone’s camera to take photos or videos, adding time and location stamps and allowing you to insert text to describe the experience. The location information allows a map of your travels to be created, while photos can be edited and effects added. You can also follow other travellers’ adventures.